Today's increased attention to nature and the environment has resulted in unprecedented efforts to encourage grasses, low-growing ground cover, and wildflowers on rights-of-way. In electric utility rights-of-way, tall growing tree and shrub species interfere with electrical line maintenance operations and if left uncontrolled can result in trees growing into power lines, resulting in power outages. On roadside rights of way, tall growing weeds interfere with water drainage from the road edge, resulting in more frequent need for road maintenance, restrict ability of motorists to use the road shoulder, cause poor vision along the right-of-way and contribute to spread of untreated noxious weed species into adjacent crop lands. In forest lands, removal of unwanted tall growing trees and woody shrubs is a frequent forest management practice in order to encourage growth of desirable tree species. Thus control treatments are required to remove tall-growing woody plants in vegetation control programs. Not only do such treatment programs result in effective, long lasting brush control, they leave non-target plants virtually untouched. This allows desired plants to thrive because they are freed from competition for moisture, nutrients and sunlight.
One such treatment program consists of the use of basal bark or stem application of an herbicide to control undesired vegetation. This particular method is attractive because it provides not only vegetation control but also efficient placement and utilization of the herbicide composition on individual plants. U.S. Pat. No. 5,466,659 describes this method of treatment with a variety of triclopy butoxyethyl ester compositions. Another such treatment program consists of the use of a foliar application of an herbicide to control undesired vegetation. This particular method is attractive because it provides not only vegetation control but, when a selective herbicide is used, desirable vegetation is encouraged.
In order to have the herbicide penetrate into the woody plant, it is desirable to dissolve the herbicide in a non-aqueous organic carrier. As currently used, as in Garlon™ 4 herbicide, for example, such carriers consists of petroleum distillates such as fuel oils, e.g., diesel oil or kerosene.
However, these carriers present risks not only to the surrounding environment, but also to the applicator as well. In aerial applications, for example, due to applicator technique or wind conditions, over-spray onto surrounding areas may result in unplanned deposition of the carriers during the application.